Expression of anti-Müllerian hormone (AMH) in the equine testis.

The research investigates the expression of Anti-Müllerian hormone (AMH) in different stages and conditions of equine testis. The findings highlight that AMH is strongly expressed in fetal, neonatal, and prepubertal equine testis but not in normal adult equines, suggesting potential utility as a biomarker in diagnosing cryptorchid testes, testicular tumors, and identifying intersex gonads in horses.

Research Objectives

• The study aimed to explore the expression of Anti-Müllerian hormone (AMH) in the equine testis at different stages of development such as fetal, neonatal, prepubertal, and adulthood. Additionally, the study evaluated the presence of AMH in horses affected by cryptorchid testes and select testicular neoplasms, as well as in intersex gonads. The ultimate objective of the research is to evaluate the potential of AMH as a biomarker for these conditions.

Methodology

• The research involved the study of equine testes sourced from fetuses at 5.5, 10, and 11 months of gestation, 12-month-old equines, and adult stallions. Testes with conditions, such as cryptorchidism, testicular tumors (teratomas, seminomas, and Sertoli cell tumors), and intersex gonads were also studied.
• Immunohistochemistry (IHC), an efficient technique to visually determine the presence and location of proteins in tissues, was used in this study. The testes were subjected to IHC for the expression of AMH using a goat polyclonal primary antibody (alpha-AMH) directed against a C-terminal peptide antigen obtained from human AMH.

Key Findings

• The study found that Sertoli cells, within the developing seminiferous tubules of equine testes, exhibited immunolabeling with alpha-AMH. This was consistent in fetal, neonatal, and prepubertal equine testes.
• However, no expression was detected in the Sertoli cells of normal adult equine testes, suggesting a decrease in AMH expression as the horse matures.
• In cryptorchid testes (in horses up to 3-4 years of age), testicular tumors (Sertoli cell tumors), and intersex gonads, AMH expression was noticeable.

Conclusion and Implication

• The research concludes that AMH is strongly expressed in fetal, neonatal, and prepubertal equine testes, but not in normal adult testes.
• The detection of AMH in cryptorchid testes, as well as its presence in certain testicular tumors and intersex gonads, may offer a promising avenue in finding a useful biomarker for these conditions. This marker can aid in the diagnosis and articular characterization of these conditions in horses.